Naturally you should start a new game file OR Rebirth.
Some times it may be fine to play with an outdated save file but depending on the severity of the update... it might become glitchy or unplayable.
So yes, try rebirth before the save becomes too outdated and starts crashing, you can do that by Giving birth and then either die some hows Or reach the ending of the game, that way you will be able to rebirth and restart the game, Except you can keep most of your EXP and all of your bank items.
if thats too difficult, then just Start a new save file.
for the most part saves are usually supported unless patch notes say that save files not saved on versions at or after X version are unsupported although in such cases you can make it supported by downloading that specific version of the game running and saving your save file on it after leaving and entering the place you were in